NAIROBI, Kenya (AP) — The U.S. State Department has closed its embassies in four sub-Sarahan African nations. It’s part of a heightened security alert — days before the 15th anniversary of al-Qaida’s bombings of American diplomatic missions in Kenya and Tanzania.

The embassies targeted in those attacks were rebuilt as more heavily fortified structures, away from populated areas. They remain open — but the diplomatic missions in Rwanda and Burundi, which border Tanzania to the west, have been closed. So have the missions in the small island nations of Madagascar and Mauritius.

The State Department has shut down U.S. facilities in countries including Egypt, Jordan, Libya, Yemen, Saudi Arabia and Kuwait. In all, diplomatic posts in 19 cities — including the four in sub-Saharan Africa — will be closed through the end of the week.

There’s no word as to why the embassies in Africa were closed. But al-Qaida operatives are still in East Africa. And one Africa expert noted that Burundi and Rwanda each have an older embassy building that is less secure than newer ones.

Even before the current embassy closings, the State Department warned that Burundi could be hit by a terrorist attack because it had deployed troops to Somalia to fight against an armed Islamist extremist group allied with al-Qaida.

APPHOTO AAS103: FILE – In this file photo of Monday, March 3, 2003, the new U.S. Embassy on the outskirts of Nairobi. The largest U.S. diplomatic mission in sub-Saharan Africa replaces the earlier mission that was destroyed by a terrorist bomb on Aug 7, 1998, killing 219 people. Wednesday will mark 15 years since that explosion. During a week of heightened security concerns at U.S. embassies the East African countries of Rwanda, Burundi, Mauritius and Madagascar were added to the U.S. embassy closures list on Sunday. (AP Photo/Khalil Senosi, File) (3 Mar 2003)